It is known to have keys which consist of multiple parts. In the past separable keys consisted of discreet parts whereby the separate parts were joined by some mechanical means.
The parts that were connected by such mechanical means and separable from the remainder of the key were the entire shank portion, a portion of the shank portion with protuberances, and an end portion of the shank portion.
In such situations, the parts were separable and the key was not formed of one piece (i.e., unibody). In most cases the separable portion could be attached and detached at the whim or necessity of the user. The keys of this type were not of a unibody construction.